Fix CMIS getContentStream for user agents that do not support RFC 5987 encoding

NXP-27337 breaks CMIS downloads for user agents that do not support RFC 5987 encoding.

Prior to Nuxeo 10.10 HF15, CMIS downloads returned the following Content-Disposition response header:

Content-Disposition: inline; filename="EURO rates"

Beginning in Nuxeo 10.10-HF15, CMIS downloads now return the following Content-Disposition response header:

Content-Disposition: attachment; filename*= UTF-8''%e2%82%ac%20rates

User agents that do not support RFC 5987 encoding are likely to have problems with the new format.

In order to provide backwards compatibility for user agents not implementing RFC 5987, link https://tools.ietf.org/html/rfc6266#page-7 suggests to return the following Content-Disposition response header:

Content-Disposition: attachment;
                          filename="EURO rates";
                          filename*=utf-8''%e2%82%ac%20rates

Note: Those user agents that do not support the RFC 5987 encoding ignore "filename*" when it occurs after "filename".